Background: Intake of sufficient dietary fiber has been recommended for glucose control, and typically low fiber intake is observed in the general population. The role of fiber in glycemic control in reported literature is inconsistent and few reports are available in populations with type 1 diabetes (T1D).
Methods: We conducted a cross-sectional analysis of data from the CACTI study [n=1257; T1D: n=568; nondiabetic controls: n=689] collected between March 2000 and April 2002. Participants completed a validated food frequency questionnaire, a physical examination and fasting biochemical analyses (12h fast) at screening visit. We used linear regression models to examine associations of total dietary fiber with HbA1c as a continuous variable. Models were stratified by diabetes status, and adjusted for age, sex and total calories, and diabetes duration in the T1D group. We also examined correlations of fiber with HbA1c.
Results: Baseline dietary fiber intake and HbA1c in the T1D group were 16g [median (IQ): 11-22g) and 7.9±1.3% mean (SD), respectively, and in the nondiabetic controls were 15g [median (IQ): 11-21g) and 5.4±0.4%, respectively. Pearson partial correlation coefficients revealed a significant but weak inverse association of total dietary fiber with HbA1c when adjusted for age, sex, diabetes status and total calories (r= -0.07, p=0.01). In adjusted linear regression models, total dietary fiber was significantly and inversely associated with HbA1c in the T1D group [estimate (beta±SE)= -0.32±0.15, p=0.034], as well as in the nondiabetic controls [-0.10±0.04, p=0.009]. Thus, at observed levels of intake, total dietary fiber reveals a protective association against poor glycemic control in T1D adults and in nondiabetic controls.
A. Basu: None. A.C. Alman: None. J.K. Snell-Bergeon: Stock/Shareholder; Self; Abbott. Research Support; Self; Roche Diagnostics Corporation.